US President Donald Trump answers questions from the media as he departs the White House toward Marine One in Washington, DC on March 10, 2018. President Trump is travelling to Pennsylvania to speak at a ” Make America Great Again ” rally on behalf of Republican candidate Rick Saccone. / AFP PHOTO / Olivier Douliery

The White House fumed Wednesday about an embarrassing leak of Donald Trump’s shock decision to congratulate Vladimir Putin on his re-election, with one official describing the disclosure as illegal.

A hunt is underway to find the person who leaked Trump’s prepared notes for the call, which included a warning “DO NOT CONGRATULATE,” which he ignored.

Trump had shunned the advice of some aides in making the call Putin at all.

He then went a step further to congratulate the Russian leader on winning a fourth presidential term, despite the election being plagued by evidence of ballot stuffing, media censorship and the jailing of political opponents.

The Washington Post and others reported that staff explicitly advised Trump not to congratulate Putin and that he should condemn the poisoning of a former Russian spy in Britain.

According to accounts from the White House and the Kremlin, Trump did neither.

The leak of such sensitive information about Oval Office deliberations points to deep frustration within the White House about his ad-hoc approach and disregard for the advice of his inner circle.

Very few officials would have known about the details of the call, only those at the very highest levels of the administration and the president himself.

Officials, speaking on condition of anonymity, told AFP that the hunt for the leaker was underway.

One official suggested the documents preparing for the call may have been classified, making unauthorized disclosure a crime.